Hello and thank you for using just answer. Can you elaborate/clarify this please???
What year/model/engine size toyota do you own?
Are you stating that the car tries to stall when not in motion?
The car is supposed to idle at around 750 rpm's once it's warmed up.
When you first start the car cold it sould rev up to about 1,500 rpm's and slowly decrease idle speed, once the engine is warm the car should idle at 750 rpm's as long as the air conditioning/defroster is not turned on. With a/c or defrost the car should idle up to about 1,000 rpm's, if this does not happen you may have a sticking idle control valve.
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